<SEC-DOCUMENT>0001193125-25-281407.txt : 20251114
<SEC-HEADER>0001193125-25-281407.hdr.sgml : 20251114
<ACCEPTANCE-DATETIME>20251114064051
ACCESSION NUMBER:		0001193125-25-281407
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20251114
DATE AS OF CHANGE:		20251114

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IRON MOUNTAIN INC
		CENTRAL INDEX KEY:			0001020569
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		ORGANIZATION NAME:           	05 Real Estate & Construction
		EIN:				232588479
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-52359
		FILM NUMBER:		251481017

	BUSINESS ADDRESS:	
		STREET 1:		85 NEW HAMPSHIRE AVENUE, SUITE 150
		STREET 2:		PEASE INTERNATIONAL TRADEPORT
		CITY:			PORTSMOUTH
		STATE:			NH
		ZIP:			03801
		BUSINESS PHONE:		617-535-4781

	MAIL ADDRESS:	
		STREET 1:		1101 ENTERPRISE DRIVE
		CITY:			ROYERSFORD
		STATE:			PA
		ZIP:			19468

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	IRON MOUNTAIN INC/PA
		DATE OF NAME CHANGE:	20000201

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PIERCE LEAHY CORP
		DATE OF NAME CHANGE:	19960807

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COHEN & STEERS, INC.
		CENTRAL INDEX KEY:			0001284812
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		ORGANIZATION NAME:           	02 Finance
		EIN:				141904657
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G

	BUSINESS ADDRESS:	
		STREET 1:		1166 AVENUE OF THE AMERICAS
		STREET 2:		30TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		212 832 3232

	MAIL ADDRESS:	
		STREET 1:		1166 AVENUE OF THE AMERICAS
		STREET 2:		30TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COHEN & STEERS INC
		DATE OF NAME CHANGE:	20040324
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
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  <headerData>
    <submissionType>SCHEDULE 13G</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001284812</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <coverPageHeader>
      <securitiesClassTitle>Common Stock</securitiesClassTitle>
      <eventDateRequiresFilingThisStatement>09/30/2025</eventDateRequiresFilingThisStatement>
      <issuerInfo>
        <issuerCik>0001020569</issuerCik>
        <issuerName>Iron Mountain, Inc.</issuerName>
        <issuerCusip>46284V101</issuerCusip>
        <issuerPrincipalExecutiveOfficeAddress>
          <street1 xmlns="http://www.sec.gov/edgar/common">85 New Hampshire Avenue</street1>
          <street2 xmlns="http://www.sec.gov/edgar/common">Suite 150</street2>
          <city xmlns="http://www.sec.gov/edgar/common">Portsmouth</city>
          <stateOrCountry xmlns="http://www.sec.gov/edgar/common">NH</stateOrCountry>
          <zipCode xmlns="http://www.sec.gov/edgar/common">03801</zipCode>
        </issuerPrincipalExecutiveOfficeAddress>
      </issuerInfo>
      <designateRulesPursuantThisScheduleFiled>
        <designateRulePursuantThisScheduleFiled>Rule 13d-1(b)</designateRulePursuantThisScheduleFiled>
      </designateRulesPursuantThisScheduleFiled>
    </coverPageHeader>
    <coverPageHeaderReportingPersonDetails>


      <reportingPersonName>Cohen &amp; Steers, Inc.</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>DE</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>12328467</soleVotingPower>
        <sharedVotingPower>0</sharedVotingPower>
        <soleDispositivePower>16029962</soleDispositivePower>
        <sharedDispositivePower>0</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>16029962</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>5.43</classPercent>
      <typeOfReportingPerson>HC</typeOfReportingPerson>
      <typeOfReportingPerson>CO</typeOfReportingPerson>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>


      <reportingPersonName>Cohen &amp; Steers Capital Management, Inc.</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>NY</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>12243203</soleVotingPower>
        <sharedVotingPower>0</sharedVotingPower>
        <soleDispositivePower>15841858</soleDispositivePower>
        <sharedDispositivePower>0</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>15841858</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>5.36</classPercent>
      <typeOfReportingPerson>IA</typeOfReportingPerson>
      <typeOfReportingPerson>CO</typeOfReportingPerson>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>


      <reportingPersonName>Cohen &amp; Steers UK Limited</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>X0</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>68948</soleVotingPower>
        <sharedVotingPower>0</sharedVotingPower>
        <soleDispositivePower>171788</soleDispositivePower>
        <sharedDispositivePower>0</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>171788</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>0.06</classPercent>
      <typeOfReportingPerson>IA</typeOfReportingPerson>
      <typeOfReportingPerson>CO</typeOfReportingPerson>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>


      <reportingPersonName>Cohen &amp; Steers Asia Limited</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>K3</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>0</soleVotingPower>
        <sharedVotingPower>0</sharedVotingPower>
        <soleDispositivePower>0</soleDispositivePower>
        <sharedDispositivePower>0</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>0</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>0.00</classPercent>
      <typeOfReportingPerson>IA</typeOfReportingPerson>
      <typeOfReportingPerson>CO</typeOfReportingPerson>
    </coverPageHeaderReportingPersonDetails>
    <coverPageHeaderReportingPersonDetails>

      <reportingPersonName>Cohen &amp; Steers Ireland Limited</reportingPersonName>
      <memberGroup>b</memberGroup>
      <citizenshipOrOrganization>L2</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>16316</soleVotingPower>
        <sharedVotingPower>0</sharedVotingPower>
        <soleDispositivePower>16316</soleDispositivePower>
        <sharedDispositivePower>0</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>16316</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
      <classPercent>0.01</classPercent>
      <typeOfReportingPerson>FI</typeOfReportingPerson>
      <typeOfReportingPerson>CO</typeOfReportingPerson>
    </coverPageHeaderReportingPersonDetails>
    <items>
      <item1>
        <issuerName>Iron Mountain, Inc.</issuerName>
        <issuerPrincipalExecutiveOfficeAddress>85 New Hampshire Avenue, Suite 150 Portsmouth, NH 03801 USA</issuerPrincipalExecutiveOfficeAddress>
      </item1>
      <item2>
        <filingPersonName>Cohen &amp; Steers, Inc.
Cohen &amp; Steers Capital Management, Inc.
Cohen &amp; Steers UK Ltd
Cohen &amp; Steers Asia Ltd
Cohen &amp; Steers Ireland Ltd
</filingPersonName>
        <principalBusinessOfficeOrResidenceAddress>The principal address for Cohen &amp; Steers, Inc.
and Cohen &amp; Steers Capital Management, Inc. is:
1166 Avenue of the Americas, 30th Floor
New York, NY 10036

The principal address for Cohen &amp; Steers UK Ltd. is:
The Burlian, 2nd Floor
3 Dering Street, London W1S 1AA
United Kingdom

The principal address for Cohen &amp; Steers Asia Ltd. is:
3301B, 33rd Floor, The Henderson
2 Murray Road
Central, Hong Kong

The principal address for Cohen &amp; Steers Ireland Ltd. is:
Suite G01
81 Merrion Square South
Dublin 2
D02 NR12
Ireland
</principalBusinessOfficeOrResidenceAddress>
        <citizenship>Cohen &amp; Steers, Inc: Delaware corporation
Cohen &amp; Steers Capital Management, Inc: New York corporation
Cohen &amp; Steers UK Ltd: United Kingdom Private Limited Company
Cohen &amp; Steers Asia Ltd: Asia Private Limited Company
Cohen &amp; Steers Ireland Ltd: Ireland Private Limited Company
</citizenship>
      </item2>
      <item3>
        <notApplicableFlag>N</notApplicableFlag>
        <typeOfPersonFiling>IA</typeOfPersonFiling>
        <typeOfPersonFiling>HC</typeOfPersonFiling>
        <typeOfPersonFiling>FI</typeOfPersonFiling>
        <otherTypeOfPersonFiling>Corporation</otherTypeOfPersonFiling>
      </item3>
      <item4>
        <amountBeneficiallyOwned>16,029,962</amountBeneficiallyOwned>
        <classPercent>5.43%</classPercent>
        <numberOfSharesPersonHas>
          <solePowerOrDirectToVote>12,328,467</solePowerOrDirectToVote>
          <sharedPowerOrDirectToVote>0</sharedPowerOrDirectToVote>
          <solePowerOrDirectToDispose>16,029,962</solePowerOrDirectToDispose>
          <sharedPowerOrDirectToDispose>0</sharedPowerOrDirectToDispose>
        </numberOfSharesPersonHas>
      </item4>
      <item5>
        <notApplicableFlag>Y</notApplicableFlag>
      </item5>
      <item6>
        <notApplicableFlag>N</notApplicableFlag>
        <ownershipMoreThan5PercentOnBehalfOfAnotherPerson>Each of Cohen &amp; Steers Capital Management, Inc., Cohen &amp; Steers UK Ltd., Cohen &amp; Steers Asia Ltd. and Cohen &amp; Steers Ireland Ltd. holds the securities of the Issuer to which this statement relates for the benefit of their respective account holders.  Such account holders have the right to receive or the power to direct the receipt of dividends from, or proceeds from the sale of, the securities of the Issuer that are held on their behalf.</ownershipMoreThan5PercentOnBehalfOfAnotherPerson>
      </item6>
      <item7>
        <notApplicableFlag>N</notApplicableFlag>
        <subsidiaryIdentificationAndClassification>Cohen &amp; Steers, Inc. holds a 100% interest in Cohen &amp; Steers Capital Management, Inc., Cohen &amp; Steers UK Ltd., Cohen &amp; Steers Asia Ltd. (investment advisors registered under Section 203 of the Investment Advisers Act) and Cohen &amp; Steers Ireland Ltd. (a non-US institution).</subsidiaryIdentificationAndClassification>
      </item7>
      <item8>
        <notApplicableFlag>Y</notApplicableFlag>
      </item8>
      <item9>
        <notApplicableFlag>Y</notApplicableFlag>
      </item9>
      <item10>
        <notApplicableFlag>N</notApplicableFlag>
        <certifications>By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.</certifications>
      </item10>
    </items>
    <signatureInformation>
      <reportingPersonName>Cohen &amp; Steers, Inc.</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Nargis Hilal</signature>
        <title>SVP, Global Chief Compliance Officer &amp; Associate General Counsel</title>
        <date>11/14/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Cohen &amp; Steers Capital Management, Inc.</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Nargis Hilal</signature>
        <title>SVP, Global Chief Compliance Officer &amp; Associate General Counsel</title>
        <date>11/14/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Cohen &amp; Steers UK Limited</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Nargis Hilal</signature>
        <title>SVP, Global Chief Compliance Officer &amp; Associate General Counsel</title>
        <date>11/14/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Cohen &amp; Steers Asia Limited</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Catherine Cheng</signature>
        <title>VP, Compliance Officer</title>
        <date>11/14/2025</date>
      </signatureDetails>
    </signatureInformation>
    <signatureInformation>
      <reportingPersonName>Cohen &amp; Steers Ireland Limited</reportingPersonName>
      <signatureDetails>
        <signature>/s/ Alan Cooper</signature>
        <title>VP, Compliance Officer</title>
        <date>11/14/2025</date>
      </signatureDetails>
    </signatureInformation>
  </formData>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
